AP Undo Like (#3933)

* AP Undo Like

* rename

src/remote/activitypub/kernel/undo/like.ts

@@ -0,0 +1,21 @@
+import * as mongo from 'mongodb';
+import { IRemoteUser } from '../../../../models/user';
+import { ILike } from '../../type';
+import Note from '../../../../models/note';
+import deleteReaction from '../../../../services/note/reaction/delete';
+
+/**
+ * Process Undo.Like activity
+ */
+export default async (actor: IRemoteUser, activity: ILike): Promise<void> => {
+	const id = typeof activity.object == 'string' ? activity.object : activity.object.id;
+
+	const noteId = new mongo.ObjectID(id.split('/').pop());
+
+	const note = await Note.findOne({ _id: noteId });
+	if (note === null) {
+		throw 'note not found';
+	}
+
+	await deleteReaction(actor, note);
+};